This invention relates generally to valves and more particularly to a double plug shuttle vale.
Valves form an essential element of many of the mechanisms in use today by accurately regulating the flow of fluids such as liquids or gas within the mechanism. In many instances it is necessary to utilize a valve which is not only capable of combining a plurality of fluids but also capable of responding to the fluid pressure associated therewith in order to regulate this flow. Heretofore such valves were operated electrically and utilized a plurality of switches in order to move an actuator to various distinct positions. These electrical valves were extremely complex in construction and although fast acting were also in many instances unreliable due to power shortages or faulty electrical connections.
Mechanical linkages were also used in this type of valves but these linkages were either too slow acting or easily jammed. In addition, pneumatic valves have been utilized and although reliable and fast acting in many instances could not provide accurate valve positioning.
O-ring type spool valves have also been used, however, this type of valve could not be used successfully for long periods of time and with systems carrying high pressure fluids. The reason for this deficiency is that the O-ring mounted on the spool moved past either the inlet or outlet port of the valve and distribution of fluid forces was such that the O-ring was forced against the lip of the port with such force that it became chipped or mutilated. In addition these valves were incapable of properly utilizing the pressure of the fluid associated therewith.
It is therefore clearly evident that improvements in the valve art are extremely necessary.